Metallization is a fabrication step that can be utilized to make interconnections among circuit elements of an electronic device. For example, a metallization process may be utilized to connect wires to bonding pads on an integrated circuit chip via ohmic contacts. In high-temperature applications, the metallization typically relies on three separate components: (1) a silicide for producing an ohmic contact with a semiconductor; (2) the top metal layer; and (3) a barrier metal between the top metal layer and the silicide. The barrier metal may be utilized to prevent diffusion, drift, and/or migration of metal atoms between the layers and/or wires of the structure. For example, the barrier may be utilized to prevent metal atom migration between the top layer metallization (including any attached electrical interconnection) and the underlying silicide contact.
Various multilayer metallurgical schemes have been proposed to achieve high temperature operability, with a temperature capability based on specific properties associated with each metal layer. However, the capability to withstand high temperatures (for example, above 600° C.) for long periods of time (for example, over 1000 hours) is limited by the diffusion, drift, and/or migration of metal atoms between the layers and/or wires of the structure.
A need exists for systems and methods for producing integrated circuits capable of reliable operation at elevated temperatures.